Lemon SqueezyMerchant of record platform to sell software, subscriptions and digital products
The base fee is 5% + 50¢ (USD) per transaction, against 10% + $0.50 on Gumroad direct sales, and it offers usage-based billing and an affiliate program.
PayhipPlatform to sell digital products, courses, memberships and coaching
The Free Forever plan's fee is 5% per sale plus PayPal or Stripe fees (Gumroad: 10% + $0.50), paid plans lower it to 2% or 0%, and courses have quizzes and certificates.
ThriveCartCheckout, sales funnels, subscriptions and course hosting for online sellers
ThriveCart states 0% fees on sales (a monthly or one-time $495 lifetime price instead), and it has A/B tests for checkouts and buy-now-pay-later options.